A wireless, battery-free gyroscope was developed by employing a one-port surface acoustic wave (SAW) reflective delay line, a SAW resonator, and an antenna. Two SAW devices with different center frequencies were simultaneously activated by one antenna with double resonant frequencies. During wireless testing, the developed gyroscope showed clear reflection peaks with high S/N ratios in both the time and frequency domains. Upon rotation of the device, large shifts of the reflection peaks were observed owing to a secondary wave interference effect caused by the Coriolis force that depends on the spinning rate. The measured sensitivity and linearity of the developed gyroscope were, respectively, 1.35 deg/(deg/s) and 0.91, which are promising values for our targeted applications. The temperature and vibration/shock effects were also characterized
|